


Moonlit Promise

by CloversDreams



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Dr. STONE Week 2020, Established Relationship, M/M, Mirai isn’t sick, Modern AU, Tooth-Rotting Fluff, Tsukasa and Ryusui are HS seniors, and will absolutely spend it together, because theyre very in love, becuz its what they deserve, no petrification, they have their whole lives ahead of them
Language: English
Status: Completed
Published: 2020-07-03
Updated: 2020-07-03
Packaged: 2021-03-04 18:08:50
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,600
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25050667
Author URL: https://archiveofourown.org/users/CloversDreams/pseuds/CloversDreams
Summary: Tsukasa turned back towards the full-length mirror and continued to try and fix his tie. He shook his head and sighed, “I don’t know why I agreed to this. It was stupid. I’m canceling.”Mirai clicked her tongue then walked into the room. She reached out to adjust his tie for him and replied, “Relax, everything will be just fine.” She smoothed out his shoulders and added, “You’re just nervous because you like him so much.”“Of course I do. We’ve been dating almost the entirety of high school.” Tsukasa said to no one in particular. Hearing it out loud was kind of amazing. It was hard to believe that time flew as fast as it did. Suddenly it was time for them to graduate and head to University. That felt surreal.“He sure is your sweetheart,” Mirai hummed with a nod.“I never said that…” Tsukasa muttered. He frowned and ignored the way he felt his cheeks start to burn. Now was not the time to get hung up on such a thing.“You didn’t have to. He said it for you. Loads of times over the years.” Mirai laughed.
Relationships: Nanami Ryuusui/Shishiou Tsukasa
Comments: 6
Kudos: 30
Collections: Dr. Stone Week 2020





	Moonlit Promise

Tsukasa couldn’t remember the last time he was so nervous. His fingers didn’t cooperate with him as he tried his best to adjust his tie. The stupid thing was broken or something. He needed to go find another one before it was time to leave. Wait. He didn’t have another one. In that case, he needed to go to the store, buy another one, and make it back here all in– _less than twenty minutes_!? He was doomed.

“Knock, knock. How’s it going in here?” Asked a sweet voice.

He turned and saw Mirai smiling at him from the doorway. She tilted her head and awaited his response, even though the answer was actually crystal clear. Tsukasa turned back towards the full-length mirror and continued to try and fix his tie. He shook his head and sighed, “I don’t know why I agreed to this. It was stupid. I’m canceling.”

Mirai clicked her tongue then walked into the room. She reached out to adjust his tie for him and replied, “Relax, everything will be just fine.” She smoothed out his shoulders and added, “You’re just nervous because you like him so much.”

“Of course I do. We’ve been dating almost the entirety of high school.” Tsukasa said to no one in particular. Hearing it out loud was kind of amazing. It was hard to believe that time flew as fast as it did. Suddenly it was time for them to graduate and head to University. That felt surreal.

“He sure is your sweetheart,” Mirai hummed with a nod.

“I never said that…” Tsukasa muttered. He frowned and ignored the way he felt his cheeks start to burn. Now was not the time to get hung up on such a thing.

“You didn’t have to. He said it for you. Loads of times over the years.” Mirai laughed. She smiled from ear to ear and added, “Even if he didn’t, it’s written plain as day on your face whenever you’re together. You’ve got a terrible case of being head over heels in love.”

Tsukasa put his right hand over his burning face and mumbled, “I really don’t need this right now, Mirai.”

“I’m just saying that you don’t need to be nervous because I see the way he looks at you too and frankly your mutual goo-goo eyes are kind of gross.” She sighed.

“Mirai!” Tsukasa gasped.

A loud knock sounded through the apartment and she giggled then skipped away. “I’ll get it!”

Tsukasa heard Ryusui’s familiar laugh and immediately found himself nervous again. One would think that this kind of thing would come naturally after being together for so long, but no. He was a certified mess. He motioned to adjust his tie but stopped when he saw that it was perfect. Oh, yeah. She’d fixed it for him. Tsukasa patted himself down quickly to make sure he had all the essentials. Everything was accounted for. Guess there was nothing left to do but greet his boyfriend.

He wandered out of his room and down the hall. Ryusui’s laughter got clearer the closer he got to the foyer. Tsukasa could hear the blond teasing Mirai about getting herself a boyfriend one of these days. Well that was never going to happen. Tsukasa wouldn’t stand for such a thing. He had every intention of telling the pair just that but as soon as he saw Ryusui his mind went blank.

His boyfriend looked way too stunning in a suit. The sight always left him breathless for a second. Tsukasa didn’t know how he’d forgotten that. His nervousness all but melted away when Ryusui turned and smiled at him. Now it was all he could do not to run up to and wrap his arms around the guy. They’d known each other for years and Tsukasa still didn’t know how he had that effect on him.

Ryusui’s eyes traveled over Tsukasa and back up again shamelessly. Their gazes met and his smile widened as he said, “Oh, wow, you look–!”

“You too,” Tsukasa nodded, “as usual.”

Ryusui’s cheeks darkened with a happy blush. He removed his arms from behind his back then stretched them all the way out to offer Tsukasa the bouquet of flowers he’d been hiding. His smile stretched across his face as he chirped, “Tada! These are for you! It’s a rainbow bouquet!”

“I can see that,” Tsukasa replied as he took the flowers. They were gorgeous and truly lived up to their name as together the bunch incorporated every color of the rainbow. Something so loud might be a little too much for most situations but somehow they suited Ryusui perfectly. For that reason alone, Tsukasa had no choice but to adore them. “Thank you.”

He picked out a single rose from the bunch then turned towards Mirai and offered them to her. He nodded and hummed, “Put them in the good vase for me?”

“You got it.” Mirai replied with a smile. She watched Tsukasa break the stem so it was short then thread the rose through the button hole over Ryusui’s breast pocket. The blond grinned, held out his arm, then waited for Tsukasa to hook his arm in his. After that the pair finally headed for the door. Mirai waved and called, “Have fun you two! Remember not to stay out past curfew!”

“We wouldn’t dream of it!” Ryusui laughed as he waved back.

“We’re eighteen we don’t have a curfew…” Tsukasa muttered under his breath before he sighed and shook his head. Ryusui simply laughed again then kissed his cheek.

Tsukasa made sure to greet the driver before the two of them got into the car. Ryusui was already chatting up a storm about how he thought it was pretty cool that their school was hosting a dance for the seniors just like they did in American schools. Though it was more of a last hurrah in this case since school was already over. It sounded like lots of fun to him and he hadn’t been able to stop talking about it for weeks. Tsukasa wasn’t as enthusiastic about the idea. However, if he got to see Ryusui so excited he supposed it wasn’t all bad.

It was so strange being at the school so late at night and in formal wear to boot. When they finally got to the gym Tsukasa almost felt like they'd wandered into another dimension. It was decorated from top to bottom and completely unrecognizable. The music in the air was so loud that it was difficult to hear himself think. That didn’t seem to stop anyone from socializing, though. He glanced at Ryusui when the blond squeezed his arm. The guy was pretty much glowing with excitement.

The two of them mingled, well, mostly Ryusui mingled while Tsukasa nodded along. That was fine, the blond did enough talking for the both of them. After chatting with mutual friends they’d probably never see again, they also greeted a few teachers that were there to chaperone. Tsukasa was surprised by the atmosphere. There was a cautious excitement as it seemed to hit everyone all at once that they’d be off to University when the next semester began.

They were invited to play a round of cards with friends and Ryusui couldn’t say yes fast enough. One turned into four before they finally called it quits. After that they wandered over to a corner where they could get a picture taken together. Ryusui kept telling the photographer that he wanted the biggest, most expensive photo package sent to his home even though the poor guy kept trying to explain that it wasn’t his job and that was handled online.

Tsukasa eventually took pity on the poor man and dragged the blond away. That was when they finally ended up at the snack table. Ryusui downed an entire cup of juice and quickly grabbed another. All the chit-chatting he’d been doing over the past ninety minutes must’ve left him parched.

Once he finished his second drink and tossed the empty cups into the trash he nudged Tsukasa with his elbow. He waited for the taller man to lean in so he’d be able to hear him then grinned. There was a mischievous gleam in his eyes as he asked, “You wanna sneak away to one of the usual spots for a final make out session in these walls?”

“Sure. But first–” Tsukasa took his hand and pulled him to the dance floor. The song had changed to a familiar slow number and he couldn't pass up the opportunity to make the best of it. They stepped close to one another and Tsukasa placed his hands upon Ryusui's waist. He hummed softly when the blond’s arms wormed their way around his neck.

The pair swayed together in time with the music. It might not have seemed like anything fancy to any onlookers, but it was enough to get their pulses racing. The rest of the world fell away around them, unimportant and frivolous. Neither of them could take their eyes off the other. The song might’ve changed, neither of them really knew. The only thing that mattered was the affection they saw in one another’s eyes.

“You look…” Tsukasa paused and considered how best to finish the thought. Incredible. Like something out of a dream. Amazing in every way. Like a vision. He blinked when he noticed a sheen to Ryusui's skin then finally said, “Sparkly.”

Ryusui tossed his head back and laughed. He smiled from ear to ear and chirped, “Thanks! I took a bath in glitter earlier!”

The two of them continued to dance as Ryusui proceeded to explain the glitter bath bomb in unnecessary detail. He talked and talked about how it was a bit small, but the glitter made up for it and that the scent was divine. It was all Tsukasa could do to watch him in awe. There was only one way to shut him up when he got like this and every fiber of Tsukasa’s being wanted to do it. But there were simply too many people around. Tsukasa looked around them and came to the conclusion that it was about time they went to one of the aforementioned usual spots.

As soon as the song ended Tsukasa took Ryusui’s hand and lead him away. Even though another slow one began and they could’ve extended their dance, he had something else he needed to do. He took Ryusui out of the gym and to the nearest stairwell. They climbed all the way to the top and then stepped onto the roof. Ah, now this was a familiar scene. How many lunches had they shared up in this exact spot over the years? How many quick kisses were stolen? Including their very first one. It was so nostalgic that his chest ached slightly knowing that it was probably the last time they’d ever step foot out here.

The stairwell door shut behind them and they could still hear the muffled music from below. It was surprisingly bright out there for the time of night. Tsukasa looked up and saw that the moon was full and shining proudly, surrounded by twinkling stars. The sky sparkled like glitter, which reminded him of the way Ryusui’s eyes shined when he was excited. Something about that was extremely motivating. He walked until they were in the middle of the rooftop then let go of his boyfriend’s hand.

Tsukasa turned around and immediately put both hands on either side of Ryusui’s cheeks. He didn’t give the blond a chance to speak before he pressed their lips together in a sweet kiss. Of course his eager boyfriend immediately leaned into it. The incredible feeling of Ryusui’s lips moving against his was almost enough to make Tsukasa’s knees give out. Not yet. He could melt after he did what he came here to do.

When they finally parted Ryusui smiled dreamily and hummed, “A kiss in the very spot where we had our first, under a starry sky, while slow music plays softly in the background? Tsukasa Shishio, you hopeless romantic!”

“All of that is coincidence. There’s a different reason I wanted to get you alone tonight.” Tsukasa admitted. He reached into his pocket and removed a small box. Yet again he felt a spike of nervousness the likes of which he hadn’t known since back when their relationship was brand new. It seemed that Ryusui was speechless for once as he stared wide-eyed at the box. Good. The moment didn’t need to be ruined by his big mouth. Tsukasa opened the box and said, “Before you leave for that university overseas, I wanted to give you this.”

Ryusui’s eyes somehow managed to get even wider as he looked down at the ring that shined elegantly in the moonlight as if it was one of the stars in the sky. “Is that…!”

“It’s a promise,” Tsukasa explained. He removed it from the box and held out his hand. Once Ryusui offered his, he slid the ring onto his finger. It fit perfectly. Tsukasa couldn’t help but think that it looked like it belonged there. He rubbed Ryusui’s knuckles with his thumb and looked him in the eyes as he said, “I’ll buy you the real thing as soon as I can. For now, I want you to have this so that whenever you’re lonely you can look down at it and know that I’m thinking about you.”

“I’ll never take it off!” Ryusui shrieked. He leaped at Tsukasa, wrapped his arms around his neck, then peppered his face with kisses. He only paused to mutter, “I can’t believe I got you stupid flowers in comparison.”

Tsukasa chuckled softly then tucked his blond hair behind his ear and replied, “They were almost as beautiful as you.”

“Stop, I can’t fall any harder for you!” Ryusui exclaimed. He kissed Tsukasa and let his lips linger against his for an extra moment before he finally hummed, “I love you.”

“I love you, too,” Tsukasa replied softly. He placed a quick kiss upon Ryusui’s forehead then smiled as the blond held up his hand and squealed happily. Tsukasa joined him in admiring the ring and nodded as he said, “I’m glad you like it.”

“Of course I do! But I won’t need to look at it because I’m lonely, you know.” Ryusui declared. He winked at Tsukasa then explained, “I’m going to call you every day and explain the lectures I sat through in agonizing detail.”

“Sounds nice,” Tsukasa nodded.

Ryusui spun around so that his back was up against the taller man’s chest. He took Tsukasa’s hands and pulled them around his waist. The pair swayed to the muffled music in the air and he reached up to caress Tsukasa’s cheek as he added, “Then I’ll have you tell me about your day.”

“I’m sure it won’t be anywhere near as interesting as yours,” Tsukasa mumbled into the back of his head.

“I’ll be sure to get you loads of souvenirs too,” Ryusui hummed. He broke free of Tsukasa’s grip except for the hand that had the ring. That one was held in the air and he spun around again so he was facing his boyfriend.

Tsukasa pulled him back up against his chest and rubbed their noses together. “I’ll probably need a bigger house.”

“Definitely.” Ryusui laughed and nodded. He maintained eye-contact with Tsukasa as he purred, “So, you see, I won’t be lonely, and neither will you.”

“Oh, really?” Tsukasa asked with a smile.

Ryusui kissed that sweet smile then hummed, “Yep, it’s a promise.”

**Author's Note:**

> Yes Ryusui could buy them rings but he knows how much it means to Tsukasa that hes able to get one he earns himself so he wont… hes def buying their future home though… with Tsukasas valuable input of course
> 
> just let these two be soft and in love and in their own little world together as they casually talk about their future.. im weak
> 
> Sassy Mirai is the best XD
> 
> theyre just so cute together im crying <3


End file.
